This section provides background information related to the present disclosure which is not necessarily prior art.
Internal combustion engines (“ICEs”) typically draw ambient air into a combustion chamber where the air and a fuel are compressed by a compression device, such as a piston-cylinder for example, and ignited to cause combustion of the air-fuel mixture. The combustion gases generally expand to do work on the compression device, such as moving the piston to drive a crankshaft for example. The combustion gases are typically then expelled from the combustion chamber through an exhaust of the ICE. Combustion of the fuel in the ICE, such as diesel, gasoline, ethanol, or natural gas for example, typically results in incomplete combustion of the fuel. Incomplete combustion can result in increased emissions being released from the exhaust, such as NOx and particulate matter (e.g. soot). Additionally, levels of NOx emissions typically increase with higher combustion chamber temperatures and higher combustion chamber temperatures can also lead to increased wear on other components of the ICE.
In order to reduce NOx emissions and combustion chamber temperatures, modern ICEs typically include an exhaust gas recirculation (“EGR”) system configured to recirculate some of the exhaust gases back into the combustion chamber. Such EGR systems can be complex and costly additions to the ICE. In some applications, such as diesel ICEs for example, EGR systems can also result in decreases in efficiency and increases in particulate matter emissions.